New Heteroleptic Copper(II) Complexes as MOCVD Precursors

New volatile heteroleptic copper(II) complexes having beta-ketoiminate (O,N) and diketonate (O,O) ligands in one molecule were tested as precursors for LPCVD of copper films. Saturated vapor pressure was measured and compared for new compounds Cu(ki)(hfa) and Cu(dpk)(hfa), where ki = pentane-2-imino-4-onato, hfa = 1,1,1,5,5,5-hexafluoro-pentane- 2,4-dionato, dpk= 2,2,6,6-tetramethyl-3-iminoheptane-5-onato. The precursors are air stable and non hygroscopic compounds with long shelf life. It was demonstrated that copper metal films can be selectively deposited on metallic surfaces in the presence of hydrogen as a gas-reactant at temperatures of 250, 300, 350 °C and pressure of 20 Torr. Si(100), SiO2 (melted quartz), stainless steel, and Cu, Al, RuO2, Ru and Ta sublayers on Si(100) were tested as substrate materials. Deposited films were analyzed and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM).